Method for application of coatings to cylindrical objects



H. G. GEHNRICH 2,694,018

METHOD FOR APPLICATION OF COATINGS TO CYLINDRICAL OBJECTS 2 Sheets-Shet 1 Filed April 4, 1952 INVENTOR Hermon 6.6ehnr1ch ATTORP JEY Nov. 9, 1954 H. G. GEHNRICH 2,694,018

METHOD FOR APPLICATION OF COATINGS TO CYLINDRICAL OBJECTS Filed April 4, 1952 2 Sheets-Sheet 2 INVENTOR. Hermon 6. Gehnnch ATTORNEY METHOD FOR APPLICATION OF COATINGS TO CYLINDRICAL OBJECTS Herman G. Gehnrich, Woodside, N. Y., assignor to Gehnrich & Gehnrich, Inc., Woodside, N. Y., a corporation of New York Application April 4, 1952, Serial No. 280,603

Claims. (Cl. 117-97) The present invention relates to a novel method for covering cylindrical objects, particularly shell cases, with a thin protective film of a liquid coating composition.

The invention is especially designed to provide a method of handling shell cases in connection with a bath of a liquid coating composition in such a manner that the outer exterior area of the shell case is entirely covered with a protective coating.

Current shortages of copper have dictated the development of substitute materials for the fabrication of shell cases and particularly cases of larger caliber such as artillery shell cases for ordnance, and more recently tests have been made with shell cases of steel instead of the usual brass. The corrosion characteristics of steel require a protective lacquer coating since corrosion, particularly on the interior of the shell case, may seriously aifect the quality of the charge within the shell. The application of the protective coating has generally been applied in a continuous method of mass production whereby the shells are carried by a suitable conveyor mechanism in inverted position and with the apertured fuse end of the shell at the top, and the shells one at a time or in groups suspended crosswise from a conveyor chain are inverted as they enter the tank so that the fuse end is completely submerged in the coating composition to insure that all portions of the interior are entirely covered. The use of a single strand conveyor is most desirable since the shell cases may be transported prior to or after the dipping operation in any direction desired. However, if the shells are loaded in series with the present dipping method, the spacing of the shells on the conveyor must be substantial because of the distance required to tip them in the lacquer tank. This results in materially decreasing production. On the other hand, if load bars were placed on this same conveyor and a number of shell cases suspended from those load bars, it becomes apparent that the radii of the turns to effect a change of direction of travel would have to be considerably larger than in the case of the shells being loaded in series.

An alternate form of conveying method is to use two strands of conveyor chain, spaced apart from one another, with load bars between the two chains. The shell cases are suspended from the load bars and again because of the spacing requirements due to the existing method of dipping, it is obvious that considerable room will be required to elfect air drying or forced drying in an oven. To oifset this objection the load bars can be transferred after the dipping operation to another .conveyor of similar nature, and in making that trans fer the load bars can be spaced closer together, thus effecting a shortening of the drying space requirements.

. stricted aperture for a fuse or the like at the o ther en d,. are passed through a liquid coating composition while.-

2,694,018 I Patented Nov. 9, 1954 suspended with the apertured end at the top and rotated while tilted at an angle to the vertical position they would normally occupy. During the rotation the objects are immersed to such an extent that the liquid level within the object reaches approximately the center point at the upper end of the object. In this manner all portions of the interior and exterior of the shell cases are subjected to and covered by the coating composition and the occurence of uncovered areas due to air pockets, particularly on the interior surrounding the apertured end, are entirely avoided.

Reference is made to the accompanying drawings wherein a suitable apparatus is shown for illustrative purposes only, whereby the method of the present in- This system of conveyor, however, cannot be used in making horizontal turns, so that if the cases, after the drying operation, are to be carried in a direction of say 90 from the point of drying, this change of direction must be effected by a rather complicated additional conveyor system or manually and the continuity of the process may be disturbed.

It has been found that two or more shells may be so handled in the liquid coating bath that they maintain a parallel relationship throughout the procedure and are most conveniently arranged with respect to the conveyor mechanism for handling in subsequent operations. In accordance with the invention cylindrical objects such as shell cases, open at one end and having a revention may be conveniently carried out. Figure l is a plan view of an apparatus for. coating the interior of cylindrical objects in accordance with the present 1nvention. Figure 2 is a side elevation of the apparatus shown in Figure 1. Figure 3 is a perspective view showing the adjustable tilting rack employed in con-.

nection with theapparatus. Figure 4 is a cross-sectional view of the coating tank illustrating the disposition and relationship of the shell cases to each other during the coating process. Figure 5 is an enlarged sectional detail, partly in vertical cross-section, showing the relationship of the shell case to the liquid coating bath just prior to the start of the process. Figure 6 is a similar view of a shell case after completion of the process. Figure 7 is an enlarged sectional detail on the line 77 of Figure 2, showing a particular suspension means for the shell cases during the process.

Referring to the drawings it will be observed that a suitable apparatus may include a tank 10 for a liquid coating composition 11, for example a lacquer, filled to the level 12 in the tank 10. Mounted vertically within the tank 10 is an adjustable tilting rack 13, detailed in Figure 3, consisting of a horizontal frame 14 converging to \l-shaped ends 15 and 16, the end 15 being nearest the entrance 17 and the end 16 being nearest the exit 18 of the tank 10. The frame 14 is adjustable vertically by virtue of the fact that it is supported at the ends by vertical members 19 and 20 which rest in transverse channel members 21 and 22 and at the extremities of these channel members are uprights 23 and 24. These uprights 23 and 24 are designed to slide within four relatively short channel members 25, 26, 27 and 28, the channel members 25 and 26- being disposed on opposite sides of the entrance 17 and the channel members 27 and 28 being disposed at opposite sides of the exit 18. The uprights 23 and 24 have a series of openings 29 and the relatively short channel members have openings 30 which are aligned and held in any desired position of adjustment by means of removable pins 31. The frame 14 may also be adjustable laterally.

Pairs of the shell cases are preferably mounted in parallel relationship in the manner illustrated in Figure 4 by means of a cross member 32 provided with means whereby the shell cases may be suspended and angularly positioned during rotation as they pass through the tank 10 and liquid coating composition 11. In the particular illustrated embodiment it will be observed that each end of the cross member 32 has a swivel 33 and the shell cases 34 are suspended by means of a hook 35 extending through the fuse aperture 36 and having a socket 37 at the upper end which cooperates with a pin ball 38 attached to the end of the cross member 32.

It will be appreciated that pairs of the shell cases suspended from the cross members 32 pass through the tank 10 in series and each pair is spaced a particular distance from the succeeding pair of shell cases, whereby a con tinuous coating and lining of the interior of the shell case is obtained.

The cross members 32 are suspended and moved through the tank 10 and above the tilting frame 14 by the following mechanism. Secured at the center of the cross members 32 is a vertical rod 39 which connects the cross members 32 with yokes 40, the opposite ends of which may be provided with rollers 41, as shown in Figure 7, which travel along the opposite sides of an I beam track -42 located above and-extending "centrally" for the length of the tank 10 through the entrance 17 to beyond the exit 18, as shown particularly in Figures 1 andcZ of :the drawings. A powen ehain ll extends direetlyi below the I beamtrack-42 and: moves-the sepa rate pairs of shell cases along as they-travelthroughthe coating composition 11 of the tank 10.

The operation of the apparatus deseribed hereinabove is substantially as follows. I It will be obsrvedthat-the.

I beam traclc-42 is disposed-a'substantial distance above the :top' of the coating. tank 10 at least-sufficient for'the bottom: of the shell casesto clear thetop of thetank 10 at the entranceand. at this'poinflthe trackslopesdowm thepower chain 43. It will be observed that the shell cases 34' encounter the frame14 andtilt"substantially' in oppositeldirections by virtue' of the'swivel points 33' in such a manner that -the -liqu'id coating composition enters thechannel' 44 surrounding "the fuse aperture'36 and then as the power chain 4-3 moves along 'the shell cases are rotatedwhile in theangular position thus assumed by frictional contactwith the tilt frame 13, as represented by Fig'ures 5 and 6. It will be appreciated as observed in Figured thatafter-a complete rotation the surfaces of the shell case/within the .air cavity 45 are 'completely coveredand protectedby a thincoating 46 of the liquid coating composition,- as shownin Figure 6 of the/drawing. The pairs of shellrcases.finaIlyJencoun-ter-the trailing end 16 of the .tilt frame 13 and eventually return to the vertical position and "emerge from the tank through the exit "18.

It will be appreciated Lhatthedevicesand contrivances described herein and illustrated in the drawings are purely for purposes of illustrating the'manner in which the present invention may be accomplished and are not to be deemed as restrictive beyond the scope of the invention as represented by the' appended claims.

I claiinz.

l. A method of coating"generallycylindrical. shell cases, open at one .end and having anlapertured wall-at the oppositeend, which comprises immersing. said shell cases into a liquid coating composition withlthe open end downwardnand tilting the shell cases at an acute formed at the opposite end of theshell .caseabout its cylindrical axis, and rotating the'shell c'aseto uniformly.

coat and cover all surfaces thereof.

2. A method of coating. elongated generally cylindrical.

open ended" objects havingian .apertured wall partially neonate-t closing at the top end which comprises immersing said objects in a liquid coating composition and tilting said objects at an acute angle to the vertical until the liquid level reaches at least the centerpoint at the top of the object, while they are rotated about their cylindrical axis, to cover the exposed surfaces of the objects with the liquid coating composition.

3. A method of coating open-ended generally cylindrical objects; havingan inwardly directed flanged wall at one end, which comprises immersing said objects and passingthe'm through a liquidcoating composition while so'immersed with the walled end upward, tilting the objects until the liquid level reaches at least approximately the centerpointof the. walled end, and rotating said objects about their cylindrical axis to subject the entire area thereof to the liquid coating composition.

4. A method of coating generally cylindrical shell cases, open at one end and having a wall and a restricted apertured opening. therein at the" opposite end, which.

comprises immersing said shell cases in a bathof a liquid coating composition, -'tilting'"the cases until the liquid.

level passesthe centerpoint of the walled end, and rotating the shell cases about their'cylindrical axis to provide.

a covering of the liquid coating composition onthe inte rior 'andexterior of the'shell case.

5. A tnethod of coating generally cylindrical. .shellcases, open at one end and having a wall and arestricted apertured opening therein at the opposite'end, which.

comprises immersing said shell cases into a liquid coating composition with the open end downward, and tilting the shell cases, with the liquid level at least. near the.

center-point of the apertured'opening, lat anacute angle to the vertical until the level of theliquidcoating composition substantiallycoincides with the apertured open ing formed at the opposite end of theshell case aboutits cylindrical axis, and rotating the. shell case to uniformly coat and cover all surfaces thereof.

References Cited in the file of this patent UNITED STATES PATENTS' 

1. A METHOD OF COATING GENERALLY CYLINDRICAL SHELL CASES, OPEN AT ONE END AND HAVING AN APERTURED WALL AT THE OPPOSITE END, WHICH COMPRISES IMMERSING SAID SHELL CASES INTO A LIQUID COATING COMPOSITION WITH THE OPEN END DOWNWARD AND TILTING THE SHELL CASES AT AN ACUTE ANGLE TO THE VERTICAL UNTIL THE LEVEL OF THE LIQUID COATING COMPOSITION SUBSTANTIALLY COINCIDES WITH THE APERTURE FORMED AT THE OPPOSITE END OF THE SHELL CASE ABOUT ITS CYLINDRICAL AXIS, AND ROTATING THE SHELL CASE TO UNIFORMLY COAT AND COVER ALL SURFACES THEREOF. 